Vegans are people who don't eat anything produced by animals, period. They claim that cow milk is for baby cows (even though cows produce more milk than the calf needs) They'd claim honey is for bees and they eat nothing but organic vegetables and sourdough bread. They are usually kind of insane, even most veggies I've spoken with agree to that. The thing is that it's impossible to argue that being vegan is healthy. There is no other way for humans to absorb enough calcium than through diary products. The only alternative is to eat vitamin pills and those things are arguably unhealthy too. For amusement you could ask a vegan if a coprophiliac could be a vegan.

In addition to the thing about cows only producing the huge quantities of milk because of hormones and selective breeding, we should also recognise that the dairy industry takes calves away from their mothers straight after birth so that humans can drink all the milk the cow produces. It would be delusional to think that farmers just take what's left after the calf has drunk it.

Arguably, this is one of the cruellest things our species does. Imagine going into a hospital and stealing new-born babies, and the level of trauma this would cause. This is essentially the same thing, as all mammals possess the biological instinct/imperative to suckle their young.

Also, there are shitloads of vegetables that have more than enough calcium. The idea that we need to drink the milk of another species in order to get enough calcium is absurd. No other species does this. All other mammals stop drinking milk once they are weaned, so there is no evolutionary precedent for humans drinking cow milk.

Why cares about a pre-human evolutionary precedent? If evolutionary theory is true, we are the progression of it! We are the precedent for drinking the milk of another animal!

Furthermore, the fresh milk of a well-cared for cow is one of the greatest renewable resources available to humans. It is intensely nourishing, and immeasurably useful for the growth and retention of muscle and fat.

I understand your point about humans perhaps being the evolutionary precedent, but what this means is we have no proof and we can kind of make it up as we go along; "humans are doing this now...we must have evolved to do it!" Personally I find discussions of what humans were "meant" to do based on evolution go around in circles and are of little relevance practically, especially since intelligence is our most significant evolved trait, and allows us to do whatever we like even if it kills us after reproductive age (eg driving cars, smoking). In our history, humans have had the intelligence to adapt to whatever food sources are available.

As far as milk being a renewable resource, it only is in the sense that cows "replace" each other on any closed farm. Once you take into account that a glass of milk took 200 litres of water to produce, and each dairy cow consumes more than 20kg of vegetable matter per day (at a feed conversion ratio of about 6 on a dry matter basis), you can see that we are squandering our resources and screwing over about a billion starving people of the world. To add to this a bit more, a kilogram of cheese requires ten kilograms of milk to produce, so that just multiplies the greed.

Basically, dairy is one of our most effective ways of saying "fuck you Somalians!"

I treat the body and mind as something sacred and my attitude toward food (as with any other fundament of life) is influenced by this. Modern society is incompatible with this. People don't appreciate the luxury of available food and it becomes an accessory of their desires. Alternately, they view it merely as fuel and readily stuff their faces between appointments or on the way to work. The body-mind-temple becomes a pigsty.